The present invention relates to a system and method for packing and transporting stacks of sheets, in particular, sheets made of fragile material.
Conventional transportation of sheet material involves arranging the sheets together, tying them with a rope or a harness and loading them on the back of a transporter or inside a container. Sometimes the sheets are first packed into a crate or a wooden box before transporting them. When delicate or fragile sheets, such as glass panes are to be transported, they can not be transported lying down but must be transported in an upright position. Conventional methods for transporting such sheets are cumbersome and not always effective in providing safe transportation. Many difficulties arise because of the way the sheets are packed for transportation and the delicacy of the material.
Conventional methods of transporting and storing glass sheets are problematic mostly due to occurrence of abrasion, denting, and other forms of damage to unprotected edges, especially corners. In addition, sheets which are loosely packaged in crates can hit one another, causing cracking and breakage.
The following patents suggest devices which attempt to solve these problem is: O""Niel in U.S. Pat. No. 1,690,873 discloses a packing device for metal sheets which includes a supporting base having lugs receiving legs to receive a tie. U.S. Pat. Nos. 2,004,626 to Hann, 2,631,723 to Ellsworth, 3,203,726 to Smith and 5,519,348 to Tucker all teach corner or edge protectors for packaging sheet materials. Smith""s corner protectors also cooperate with hoist elements. U.S. Pat. No. 4,101,109 to Edwards shows a harness for a loudspeaker which includes corner pocket members.
In order to use these conventional corner protectors, one must have a large supply of many sizes so that one can find the propel corner protector that fits the particular thickness of a stack of sheets to be transported or stored. Partially relating to this problem, Cox in U.S. Pat. Nos. 4,201,138 and 4,265,184 teaches a corner board for pallets which includes a corner board cap and a filler section for loads of different heights.
In short, it would be very desirable to have adjustable protecting units, which can be easily modified to the specific thickness of any stack of sheets of any variety of dimension and weight, and which can cooperate with hoist equipment.
The present invention aims at providing a novel system for packing, storing and transporting sheet material which is efficient, safe and simple to use, and which includes modular protecting units which are easily adjusted to the desired thickness of a sheet stack to be transported.
Further object of the present invention is to provide a packing and transporting system for use with conventional strapping and/or harnesses and common hoist, crane or forklift.
Another object of the present invention is to provide a substitute system for the common wood-based crates or metal L-shaped or A-shaped frames used in the glass industry to pack, store and transport large stocks of glass sheets. The system of this invention can be also used for packing and transporting sheets of plastics, large marble plates or any other sheets or plates.
Yet another object of the present invention is to provide a packaging method which uses these protecting units for improved secured transportation and storage of sheet material.
The present invention refers to a system for packing, storing and transporting, particularly in a vertical position, stacks of sheet material such as glass, metal, plastic and large marble plates. While the invention can be used with any sheet material, it is particularly useful for transporting sheets of fragile material. Thus, for the purpose of the present invention the term xe2x80x9cglass sheetxe2x80x9d will be used in the specification to refer to any sheet material to be transported.
The present invention provides, for use in packing, storing and transporting sheet material, a sheet material protecting unit including two complementary protecting elements, each including a substantially planar surface for engaging an outer surface of the sheet material and at least one coupling element for coupling the two protecting elements, so that the sheet material is held tightly between them to prevent the sheets from moving relative to one another. Preferably, the unit also includes at least one strap engaging element for engaging tying elements, such as straps, around the stack, and at least one means for coupling lift means. When, for example, four such protecting units are assembled around the corners of a rectangular stack of sheets, the sheets are held as one rigid block, and the stack can easily be lifted by a crane.
Another embodiment of the present invention discloses a sheet material protecting system including at least two modular protecting units that are assembled around a stack of sheets and means for tying these protecting units on the sheet material.
Furthermore, the present invention provides a method for packing a stack of sheet material, comprising the steps of coupling at least two protecting units about the stack, each protecting unit being formed by coupling at least one coupling element to a first protecting element; and coupling a second protecting element to said coupling element.